The invention relates generally to valve controllers for use in a plant or factory automation environment. More specifically the invention relates to solenoid piloted valve controllers used in Foundation Fieldbus (FF) networks.
FF networks are commonly used in process plants to provide power and control signals to field devices that control the position of control valves. FF networks are fully digital and operate on limited power. 10-30 mA of current at between 9 to 32 Volts are typical levels. Therefore, field devices that are powered on the FF network need to function on very low power. Traditional discrete automated valve controllers use piezo pilot valves to drive a larger spool valve which shuttles air to pneumatic actuators to turn process valves. Piezo technology allows the field devices to function at the low powers provided by the FF network.